Electrostatic mist precipitator

ABSTRACT

An electrostatic precipitator for removing mist from a gas stream. A precipitator formed of electrical insulating material, typically resin impregnated glass fiber. A precipitator with a plurality of tubular flow passages, each having a rod conductor within the tube and another conductor within the tube wall. A helical wire conductor embedded between resin impregnated glass fiber layers to form a tubular flow passage.

United States Patent 1191 Olson Aug. 7, 1973 [54] ELECTROSTATIC MIST PRECIPITATOR 2,937,709 5/1960 DeSeversky 55/137 X [76] lnventor: Rodney l. Olson, 2080 Balmer Dr., OR IG PATENTS 0R APPLICATIONS L08 g Calif- 90039 734,207 7/1955 Great Britain 55/155 [22] Filed' Oct 1 1971 299,476 7 1917 Germany 55/150 [21] Appl. No.: 185,726 Primary Examiner-Dennis E. Talbert, Jr.

Attorney-Walton Eugene Tinsley 52 us. c1 55/146, 55/148, 55/152,

55/155, 55/010. 38 [57] ABSTRACT 51 1m. 01. B03c 3/06 All elwwsmic Precipitamr for removing mist from a 581 Field of Search 55/146, 150, 151, gas team A vrecipitamr formed of electrical insulat- 5 5 52 54 55 DIG. 3g ing material, typically resin impregnated glass fiber. A precipitator with a plurality of tubular flow assages, 5 R fer s Cited each having a rod conductor within the tube and an- UNITED STATES PATENTS other conductor within the tube wall. A helical wire conductor embedded between resin impregnated glass 12:21:: 2/1212 2 1:1; to form 1,884,086 10/1932 Miller 55/108 X 1 Claim, 3 Drawing Figures OUT 1 ELECTROSTATIC MIST PRECIPITATOR small moisture particles into larger particles which fall down through the gas stream or (YI'IICITCOHGCI'ISQ on the inner walls of the unit and ruri down the wall. The larger liquid particles are collected at the bottom of the unit and removed through a conventional drain line. The gas and/or the liquid often are highly corrosive and adversely affect the operation and the life of the precipitator.

It is an object of the present invention to provide a new and improved electrostatic precipitator particularly suited for use with corrosive gases and liquids. A further object is to provide such a precipitator which will operate in the same manner as conventional electrostatic precipitators while having substantially longer operating life and longer operating period without maintenance.

The electrostatic precipitator of the present invention may be made of an electrical insulating material such as resin impregnated glass fiber rather than the conventional lead sheathed steel. The precipitator of the present invention includes a plurality of tubular flow passages, with the tube walls formed of electrical insulating material and having a metal electrical conductor embedded within the tube wall.

The invention also comprises novel details of construction and novel combinations and arrangements of parts, which will more fully appear in the course of the following description. The drawing merely shows and the description merely describes a preferred embodiment of the present invention which is given by way of illustration or example.

In the drawing:

FIG. 1 is a side view, partly in section, of an electrostatic precipitator incorporating the presently preferred embodiment of the invention;

FIG. 2 is a sectional view taken along the line 22 of FIG. 1; and

FIG. 3 is an enlarged sectional view taken along the line 3-3 of FIG. 1.

The precipitator includes a lower housing and an upper housing 14 interconnected by tubes 11, 12 and 13. An electrical power supply 15 may be carried on the upper housing 14 on flanges 17, 18. Support legs 19 are provided on the lower housing 10 which also incorporates a drain line 20 with shut-off valve 21. A line 24 for a source of gas is connected to the lower housing 10 at inlet flange 25. Another line 26 for outflowing gas is connected to the upper housing 14 at outlet flange 27. Removable access plates 28, 29 maybe provided on the lower and upper housings, respectively. Viewing ports 30, 31 may be provided in the housing 14 if desired.

Rods 34, 35, 36 are positioned within the tubes 11, 12, 13, respectively, on frames 37, 38, with the frame 37 suspended from the upper housing 14 on electrical insulating supports 39.

The rods 34-36 are electrical conductors and typically may be straight metal bars or tubes. A preferred construction for the rods is shown in FIGS. 1 and 3 where each rod has a core 42 of electrical insulating material, typically a cylindrical polyvinyl chloride bar,

with a helical wrapof metal wire 43. The wire 43 may be a conventional smooth wire but preferably is a Starr type wire with a plurality of outwardly directed points 44.

The tubes 11l3 incorporate electrical conductors.

and'have inner linings of electrical insulating material. In the preferred form of the tubes, a helical conductor 47 is embedded between inner and outer layers 48, 49 of electrical insulating material. The tubes may be produced by applying a resin impregnated glass fiber cloth on a mandrel to form the inner layer 48, winding a metal wire 47 over the layer 48, applying a resin impregnated glass fiber cloth over the wire 47 to form the outer layer 49, and curing the resin to produce the rigid tube structure.

The tubes 11-13 may be joined to the housings 10, 14 by annular flanges 51. It is preferred to form the housings and the flanges of electrical insulating material, typically resin impregnated glass fiber, providing enhanced protection against corrosive gases and liquids. The frames 37, 38 are formed of electrical insulating material, typically polyvinyl chloride bars. One terminal 52 of the electrical power supply 15 is connected to the rods 34-36 by cables 53. The other terminal 54 of the power supply 15 is connected to the conductors 47 in the tubes 11-13 by cables 55. In the preferred embodiment illustrated, all portions of the apparatus except the electrical conductors of the rods and the cables from the power supply, are formed of electrical insulating material having high resistance to corrosion. The exposed cables and conductors may have to be removed from time to time for cleaning and/or replacement, however the remainder of the precipitator is not subject to corrosive action and will have an extremely long operating life.

In operation, an electrical potential is provided by the power supply between the centrally disposed rods and the inner periphery of the tubes. The moisture laden gas is introduced into the housing 10 through the inlet 25 and flows upward through the electric field within the tubes to the upper housing 14. As the gas passes through the electric fields, the small moisture particles are combined to form larger particles which fall downward to the bottom of the housing 10 and which collect on the inner walls of the tubes and run down to the lower ends of the tubes, dripping off into the housing 10. The liquid collected in the housing 10 may be drained continuously or periodically as desired. The substantially moisture free gas stream leaves the upper housing through the outlet 27. Although an exemplary embodiment of the invention has been disclosed and discussed, it will be understood that other applications of the invention are possible and that the embodiment disclosed may be subjected to various changes, modifications and substitutions without necessarily departing from the spirit of the invention.

I claim:

1. In an apparatus for removing mist from a gas stream, the combination of:

a lower housing having a gas inlet and a liquid outlet;

an upper housing having a gas outlet, said lower and upper housings being formed of resin impregnated glass fiber;

a plurality of tubes interconnecting said lower and upper housings, defining a gas flow path through said gas inlet, lower housing, tubes, upper housing prising a core of electrical insulating material helically wrapped with a metal wire incorporating a plurality of outwardly directed points;

suspension means for positioning one of said rods in each of said tubes; and

means for connecting an electrical power supply to said conductors of said tubes and to said wires of said rods to establish an electrical field between each tube and the rods therein.

* t 1 i i 

1. In an apparatus for removing mist from a gas stream, the combination of: a lower housing having a gas inlet and a liquid outlet; an upper housing having a gas outlet, said lower and upper housings being formed of resin impregnated glass fiber; a plurality of tubes interconnecting said lower and upper housings, defining a gas flow path through said gas inlet, lower housing, tubes, upper housing and gas outlet, said tubes supporting said upper housing above said lower housing, each of said tubes comprising inner and outer layers of electrical insulating material with a helical electrical conductor embedded between said layers; a plurality of electrical conducting rods each comprising a core of electrical insulating material helically wrapped with a metal wire incorporating a plurality of outwardly directed poiNts; suspension means for positioning one of said rods in each of said tubes; and means for connecting an electrical power supply to said conductors of said tubes and to said wires of said rods to establish an electrical field between each tube and the rods therein. 